The Housing Minister Terry Redman says he will not give special treatment to a Perth grandmother who has been refused a place on the priority waiting list.

The State Opposition yesterday highlighted the case of Diane Robinson, who cares for three of her grandchildren at the request of the Department for Child Protection.

She has to vacate the house she has been living in by March, and despite having letters of support from DCP and the Health Department, Homeswest says she can afford a private rental.

Mr Redman has told ABC Local Radio, Ms Robinson can appeal against the decision, but he will not step in.

"The thing that I won't do as a Minister is intervene on saying, of the nearly 3,000 that are on the priority waitlist now, that they are a lower priority or that she should be given special treatment," he said.

"Even if she was to go onto that waitlist, you've still got a median wait time of 43 weeks.

"We certainly don't want to see people in that situation but there are some very, very compelling cases.

"What I won't do, is intervene and use my influence to put one over another.

"That's not my role as Minister and nor should I be there."

The WA's Council of Social Service says Ms Robinson's experience is shared by many people.

The council's Irina Cattalini says a lack of affordable rentals in WA and long waiting lists for state housing is leaving vulnerable people with few options.

"There's only a long-term solution in terms of increasing the supply of affordable housing," she said.

"It relies on a commitment across governments that they will invest each and every year until we can get back to a reasonable proportion of all the housing stock that is made available for public housing and crisis accommodation.

"Even if this person was put onto the waiting list, she's still going to be facing over a year, and the normal wait list over 130 weeks, so its not really a feasible option for people, and so many people are having to rely on crisis accommodation services."